Time is the blind rider, a force nobody can unsaddle, ravaging all that appears enduring, transforming landscapes, reducing dreams to ashes. Juan Goytisolo, Spain's most significant living novelist, began writing this lyrical book of mourning and memory in November 1996, a month after the death of his wife, Monique Lange. It took him six years to complete.

The protagonist of this fictional memoir never expected to outlive his wife, and the loss of her overwhelming vitality has led to a shrinking of his world. And yet there are ambiguities in his memory. He recalls her devastating words to him, expressed with a casual gentleness: "Living with you is like serving an apprenticeship in solitude. I don't know whether I should reproach you or be grateful." Therein lies the central paradox in this remarkable work: despite his alienation from his wife and his disgust with humanity, he is ultimately brought closer to both through the power - and destructiveness - of memory. Desperate to keep his own memories alive, he nevertheless describes the notion of the eternal as a "calamitous, rustic invention".

An insomniac, his mind lurches from one reminiscence to another. He plunges 50 years into the past in search of his childhood in his father's vast farmhouse, evoking Tolstoy's Yasnaya Polyana mansion to do so. The Russian author's works have accompanied him everywhere. ("Tolstoy's characters embodied his dreams of a more intense, varied life. It was then he discovered freedom only existed in books.") He remembers the trampled, mutilated thistle he saw in Chechnya, which recalls Tolstoy's obsession in his last major work, Hadji Murat. He admires Tolstoy's desire to free the serfs from slavery and ignorance and bring up their children in line with progressive humanist principles, casting off their chains of ignorance and basking in the light of education, but points out that the peasants resist this preaching and cling to their icons and rituals.

To assuage the pain of the loss of his wife, he revisits an "older scar" - the death of his mother in a fascist air raid over Barcelona (the same fate that befell Goytisolo's own mother). However, the memory is overpowered by a recollection of the military tunes broadcast by Spanish radio towards the end of the civil war, the lapping waves of lines and lyrics swamping his mind like polluted seaweed being washed up by the tide.

His Swiftian disillusionment with the human race seems acutely heartfelt, rather than ironic: "Why did people persist in procreating and cramming that planet of dwindling resources? Didn't they realise the illusory desire for survival was the origin of fresh disasters, that the way of the world was leading to its ruin? What enlightened despot would finally summon up the courage and honesty to state this categorically and sterilise all his subjects?"

For all the angry rejection of any facile humanism, however, there is never any doubt that the protagonist opposes all forms of tyranny. Goytisolo, who lives in Marrakesh and whose books were banned in Spain until 1976 (the year after Franco died), has seen his fair share of horrors. He has reported on the wars in Chechnya and Bosnia and denounced the mindless brutality he saw there, just as he had earlier rebelled against what he saw as his mindless religious upbringing. Similarly, the central figure in The Blind Rider rages against a perverse deity amused by the deeds of ill-doers, a god who tells him: "You are now entertained by televised images of wars, mutilated bodies and the savagery of the soldiery, unaware that I've been enjoying them from the day you conceived me ... I know you don't believe in me, but you are powerless before those who do."

Goytisolo told one interviewer: "In my opinion, the most significant works of the 20th century are those that rise beyond the conceptual tyranny of genre: they are, at one and the same time, poetry, criticism, narrative and drama." In an excellent translation, Goytisolo's haunting book meets this definition supremely.